1. Field of the Invention
The present invention relates generally to authentification by use of coding, more particularly to authentification by use of coding inclusive of a printed code for an article, and most specifically to authentification by use of coding inclusive of a printed code upon an article and coding generated with, stored, and accessed as computer processed digital data.
2. General Background
Authentification is broadly recognized as encompassing three approaches, often used together in tandem or all at once: physical distinction, human judgement, and coding. Objects made in gold commonly carry a mark indicating gold content in karats: 14k, indicating 14/24 parts or 58% gold; 18k for 75%, et cetera. Silver is typically marked as ‘sterling’ indicating at least 80% silver content or 0.800, 0.850, 0.925, and often carries other marks indicating the maker, the year, the country, et cetera. And these marks can follow a code. Letters of the alphabet, in succession and in successive series of fonts, indicate the year on silver made in England one to two centuries ago, for example.
But physical distinctions can be imitated and human judgement is usually necessary to determine a genuine article from counterfeit. Solid silver is readily distinguished from plate with a single glance at the object by many people and real diamonds readily distinguished from zirconium. Anyone can tell a poorly made counterfeit note from genuine but well made counterfeits are readily detected only by experts. Printed articles are particularly susceptible to counterfeit since photocopying and digital imaging technologies have become so advanced and inexpensive.
Authentification of antiquities is considered to be almost purely an exercise in human judgement and the very high proportion of suspected counterfeits illustrates the inadequacy in relying upon unobjective human judgement alone. The materials used are often relied upon in support of human judgement. Chemical analysis readily determines the percentage silver or gold in an article and carbon dating has ruined the business in counterfeit prehistoric remains but a Van Gogh is a Van Gogh mainly because people are agreed upon the matter, as evidenced by the style and quality of the painting itself with paintings formerly attributed to an artist of the stature of Van Gogh being occasionally re-considered. In brief, objective physical evidence is not easily obtained if the counterfeiter is careful to use materials consistent with the period or particular method of manufacture.
Relying upon either skill or physical technology to render counterfeiting more difficult is seen to have certain limits owing to reliance upon human judgement. In lieu of evidence gained by scientific method, generally through chemical analysis, any human judgement is susceptible to error and any escalation in skill or technology required for evaluation is counter productive from the perspective of the public. Karat and silver marks assure the prospective legitimate, or illegitimate, acquirer who neither trusts their eye nor desires to perform a chemical analysis. Marks identifying the maker provide a similar and more pertinent assurance. Older silver or gold articles stamped ‘Tiffany’ command a higher value than an otherwise identical article because the maker is identified.
Identification of the maker adds value in this case and in many others. In this case the intrinsic value of the article is readily apprehended and the gold or silver content easily confirmed. The article is also well made and one may ask why the mark of the maker alone adds value to the article. The simple answer is that the public at large has come to recognize the ‘Tiffany’ mark and that marks generally facilitate commerce in providing the acquirer assurances regarding the authenticity of the article concerned. The public does not examine their currency for counterfeits but their familiarity with the rather intricate designs used enable at least poorly made phony paper currency to be detected. The material is also relied upon with specially made paper that is prohibited for other uses.
Both physical characteristics and human judgement are hence seen to be relied upon in detection of counterfeits generally. And both marks and printed designs are seen to rely upon material characteristics. Anyone can stamp a silver or gold article with marks but the cost of making the article takes all the profit out of the endeavor: it is more economic to use one's own mark on good silverware or articles made with gold.
There is also little to deter a counterfeiter of pharmaceuticals from reproducing the packaging, container, and all other physical evidence available to the public. Not even chemical analysis is readily applicable for positive identification of modern pharmaceuticals and pharmacists today do not have the time to perform chemical analysis to verify the product in any case: it is not economic. The public and the pharmacist both desire the assurance that the pharmaceuticals are genuine and the manufacturer certainly desires provision assuring that: this is their manufacture and this is the product, or article, that is expected.
Registration numbers are a commonplace, for automobiles and other tangible items as well as intangibles such as licenses to drive the automobile. But registration is useless to product such as pharmaceuticals because registration can only relate a number held in a registry to a person, identified by various means such as physical appearance, residence address, birth date, mother's maiden name etc. Registration largely begs the question of authenticity of an article, particularly with identification of the maker of the article in question, because it can only associate a number with an owner and the maker is incidental.
This leaves coding in its modern sense as generally used for obscuring the content of transmissions or for facilitating machine vision: i.e. encryption, bar code, radio frequency identification (RFID). The use of coding itself in authentification of articles is practically unknown to the prior art as physical evidence is always involved. The most pertinent known reference in this regard, further containing a detailed discussion of the prior art applicable to the present invention, is U.S. Pat. No. 6,463,541: ‘Object Authentification Method Using Printed Binary Code and Computer Registry’ issued Oct. 8th 2002 to the present inventor and hence does not constitute prior art.
3. Discussion of Prior Art
With regard to prior art by others it is first noted that the term ‘authentification’ is recognized as having been used for over 25 years as a term used to describe technology relating to protection against counterfeiting, of printed documents such as currency, and information transmitted in digital form. This is seen in the title of a number of U.S. patents over this period including the patent in the name of the present inventor noted above and earlier examples from the prior art:    1 U.S. Pat. No. 4,037,007: ‘Document Authentification Paper’issued in 1977;    2 U.S. Pat. No. 4,874,188: ‘Fiduciary or Security Object Enabling Visual or Optical Authentification’;    3 U.S. Pat. No. 4,893,338: ‘System Conveying Information for the Reliable Authentification of a Plurality of Documents’;    4 U.S. Pat. No. 5,131,038 ‘Portable Authentification System’.    5 U.S. Pat. No. 5,652,794: ‘Device & Process for Securizing a Document & Graphic Message Authentification Code’;    6 U.S. Pat. No. 6,189,096: ‘User Authentification Using A Virtual Private Key’;    7 U.S. Pat. No. 6,363,151: ‘Method & System for Subscriber Authentification and/or Encryption of information’.
Other US patents use the term ‘authentification’ in the same sense in the abstract if not the title including:    8 U.S. Pat. No. 5,148,007: ‘Method For Generating Random Numbers For The Encoded Transmission of Data’; and    9 U.S. Pat. No. 6,401,204: ‘Process for Cryptographic Code Management Between First and Second Computer Units’
Securing data transmission, however, is not relevant to the present invention except for the use of public key encryption technology. This ‘crypto-system’ technology was first set forth by W. Diffie and M. Hellman in the article ‘New Direction in Cryptography’ published by IEE Transactions on Information Theory, Nov. 1976:                Public key cryptosystem, which relies upon two invertible transformations: f{Kd, P}=C, and f{Ke, C}=P, both P and C are on a finite space, possesses the following properties: Kd is inverse of Ke for every n in a finite space, 2) f{Kd, P} and f{Ke, C} are both easy to compute, 3) given n, and f{Ke, C}, Kd is computationally infeasible to derive from Ke, 4) for every n, it is feasible to compute the inverse pair Kd, Ke.        Property 3) deploys the difficulty of computing logarithms over Galois Field under modulo q with one number q of elements, e.g. for a primitive element αin GF(q), Y=αx mod q for 1≦x≦(q−1) is easy to compute given x, but x=logαY mod q given Y, is difficult. Should logs mod q become easily computed; then the public key encryption system would be vulnerable;since developed as related below with regard to more pertinent cryptographic technology.        
A popular and effective algorithm for use in public key encryption technique was set forth in ‘A Method for Obtaining Digital Signatures and Public Key Cryptosystems’ by R. Rivest, A. Shamir, and L. Adleman of Massachusetts Institute of Technology published February 1978 in Communication of AMC. The algorithm effects what is known as block cipher in which each block size≦ log2(n) and n=p*q with p and q both being large prime numbers. With P=the plaintext and C=the cipher, the following algorithm is given:C=Pe mod(n); P=Cd mod(n)=(Pφ)d mod(n)=(Pe)d mod(n)=ped mod(n).Application of the Euler theorem upon the second expression above implies that ed≡1 mod φ(n) which is recognized as the Euler quotient function:φ(n)=φ(p*q)=φ(p)*φ(q)=(p−1)*(q−1).
As disclosed by William Stallings, in ‘Cryptography and Network Security: Principles and Practice’, 1998, the application of Modulo Arithmetic facilitates calculation of inverse function private and public keys with arbitrary selection of e, a small prime number relative to φ(n) and 1<e<φ(n), and calculate d using d=e−1 mod φ(n), wherein tedious key calculations are avoided and a key generator program can provide a convenient way to select large quantities of key pairs without compromising d, p & q.
4. Statement of Need
Reliance upon physical distinction and human judgement in authentication of articles and identification of the legitimate owner is limited by being essentially unobjective and of little use to the public in providing assurances of authenticity for articles that are easily copied and lacking in obvious or easily discerned intrinsic value. Pharmaceuticals are perhaps the best example of the futility of relying upon appearance of manufacture because the actual product is virtually invisible and all attempts to mark the product, by shape, color, markings, and packaging, are easily duplicated and verification of actual product economically infeasible.
While coding techniques inclusive of public key encryption have been successfully utilized in protection of data transmission use of coding in authentication of physical objects has been generally limited to serial codes placed on objects such as silverware, paper currency, registration systems associating a number with a person, and coding of numbers associated with financial documents. Coding is considered best suited to use in concealing content of communication and authenticating communication but of very limited value in providing authentification of objects because communications are both non-physical and uni-directional. Written communication is composed of a serial arrangement of characters as digital communication is comprised of a serial organization of bytes. Both are systemic abstractions directly translated by code or converted into mathematics essentially without leaving, or requiring, a physical trace.
Traditionally, relations between information are established by using a two dimensional table or relational database, wherein rows (tuples) represent an item, entity or some fact, and columns (attributes) represent properties of those entities or facts. A specific property for a specific entity is written in the cell where the row meets the column. This approach is not only-inefficient, but also open to compromise because the relationship is artificially put into the ‘cell’, as there are no scientific rules to bind the relations. That is the reason a database must be highly ‘guarded’ externally and internally. As a result the data containing the properties for each entity can not be distributed to that entity.
Traditional methods for authentification of physical objects have been seen to rely heavily upon physical evidence, usually requiring the exercise of human judgement, as one might expect, because the subject concerned is physical and not an abstraction. An inherent, fundamental, difference in the quality of the subject: abstract versus physical entities is concerned. Many physical articles, however, are easily counterfeited, especially printed material relied upon for identifying product such as pharmaceuticals that are intrinsically resistant to human judgement of the article directly.
In brief coding is considered inimical by nature to authentification of physical objects while suited to concealing communication content because both are of the same stuff: abstractions, and more specifically abstractions using unidirectional processing of discrete characters. And the traditional methods of authentification relying upon human judgements is often subjective, difficult for an average member of the public, and ineffective for many physical articles; particularly essentially opaque articles regarding an easily verifiable identity, such as pharmaceuticals.
It is noted that the identity of the maker of the physical article together with the identity of the article, i.e. authenticity, is often of primary concern while for many products such as pharmaceuticals the identity of the owner is of secondary importance while establishing legitimate ownership is the primary concern of many other objects, such as jewelry or silverware, that are readily authenticated. It is further noted that provenance is often relied upon in establishing both legitimate ownership and authenticity.
A need is hence discerned for a means of authentification for physical entities facilitating both authentication of a physical object and identification of the legitimate owner that does not require exercise of human judgement and is capable of identifying the maker, the article, and provenance.